Disc Medicine announced on Jun. 10 that it has reached an agreement with the Food and Drug Administration to resubmit its application for bitopertin, a treatment for a rare blood disorder. The FDA will allow Disc to use data from its ongoing Phase 3 APOLLO trial in support of a new regulatory filing for the drug.
BMO Capital Markets said in a note to investors that this development provides "more confidence in the regulatory path for bitopertin" and could lead to a full approval submission. If progress continues as planned, BMO said the drug may be considered for approval by mid-2027.
Bitopertin previously faced setbacks when the FDA rejected Disc's application in February, citing concerns about the adequacy of surrogate endpoints used in its Phase 2 trial. The agency questioned whether percent change in whole-blood metal-free protoporphyrin IX was a reasonable predictor of clinical benefit. The rejection letter stated that an adequate and well-controlled Phase 3 trial measuring clinical outcomes would be required before reconsideration.
The journey toward approval has been marked by controversy, including reports that Vinay Prasad, former director of the Center for Biologics Evaluation and Research, was skeptical of bitopertin and allegedly interfered with its review process. Recent leadership changes at the FDA include Prasad's departure at the end of April and subsequent replacements within key positions at the agency.
Bitopertin is designed as an orally available molecule targeting glycine transporter 1, which plays a role in hemoglobin production. Erythropoietic protoporphyria, the condition targeted by bitopertin, causes sensitivity to sunlight and artificial lights leading to severe pain; it can also be associated with liver and gallbladder complications.
Former FDA Commissioner Marty Makary has also stepped down recently amid what some have called one of the most challenging periods in agency history.
